A color erasing apparatus which erases an image on a sheet by carrying out a color erasing processing, such as heating the sheet on which the image is formed with a color erasable material to enable the color erasable material in a colored state to be in a color erased state, is known. In such a color erasing apparatus, there exists an apparatus for reading the image on the sheet before the color erasing processing and storing image data. In addition, in the color erasing apparatus, there exists an apparatus which distributes a sheet to one of the discharging destinations—a reusable sheet stacking section for stacking reusable sheets or a rejected sheet stacking section for stacking not-reusable sheets—according to a determination on whether or not an image such as characters written with a pencil or a pen remains on the sheet by reading the color erased surface of the sheet again after the image erasing processing.
The sheet placed in the color erasing apparatus for color erasing processing is a sheet which has been subjected to image forming processing, or a reusable sheet which has been subjected to the color erasing processing. Therefore, flaws in appearance and/or condition such as a rip or creases and the like possibly occur on the sheet. Such a sheet with flaws in appearance and/or condition is not suitable for later reuse.
In addition, when the image on the sheet is read by a scanner, for example, if a corner of the sheet is damaged, the damage can be recognized through the analysis on the image read in a planewise manner.
However, if the sheet is only read simply in the planewise manner, the flaws in appearance of the sheet, such as a rip, creases and the like, cannot be recognized through the analysis.